Division by 0 in `ResourceScatterDiv`
### Impact
The implementation of `tf.raw_ops.ResourceScatterDiv` is vulnerable to a division by 0 error:
```python
import tensorflow as tf
v= tf.Variable([1,2,3])
tf.raw_ops.ResourceScatterDiv(
resource=v.handle,
indices=[1],
updates=[0])
```
The implementation
https://github.com/tensorflow/tensorflow/blob/8d72537c6abf5a44103b57b9c2e22c14f5f49698/tensorflow/core/kernels/resource_variable_ops.cc#L865 uses a common class for all binary operations but fails to treat the division by 0 case separately.
### Patches
We have patched the issue in GitHub commit 4aacb30888638da75023e6601149415b39763d76
https://github.com/tensorflow/tensorflow/commit/4aacb30888638da75023e6601149415b39763d76.
The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.
### For more information
Please consult our security guide
https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md for more information regarding the security model and how to contact us with issues and questions.
### Attribution
This vulnerability has been reported by members of the Aivul Team from Qihoo 360.